Borescope plug assembly for gas turbine engine

Abstract

A borescope plug assembly includes a borescope plug having a shaft section and a tip section, a bushing engageable with the shaft section and a seal engageable with the tip section.

What is claimed is: 
     
       1. A borescope plug assembly comprising:
 a borescope plug having a shaft section and a tip section; 
 a bushing engageable with said shaft section; and 
 a seal engageable with said tip section, 
 wherein said seal is movable axially and radially relative to said tip section. 
 
     
     
       2. The borescope plug assembly as recited in  claim 1 , wherein said tip section includes a semi-spherical tip. 
     
     
       3. The borescope plug assembly as recited in  claim 1 , wherein said tip section defines a diameter less than said shaft section. 
     
     
       4. The borescope plug assembly as recited in  claim 1 , wherein said seal defines an outer diameter less than said bushing. 
     
     
       5. The borescope plug assembly as recited in  claim 1 , wherein said seal defines an inner diameter less than said bushing. 
     
     
       6. The borescope plug assembly as recited in  claim 1 , wherein said tip section and an inner aperture of said seal define an approximate 0.005 (0.127 mm) radial gap. 
     
     
       7. A gas turbine engine comprising:
 a borescope plug; 
 a multiple of bosses in a gas turbine engine structure, at least one of said bosses defines a borescope boss, said borescope boss having a through bore having an internal step; 
 a bushing mounted in said bore axially displaced from said internal step; and 
 a seal mounted in said bore between said bushing and said internal step, 
 wherein said seal is movable axially and radially within said bore relative to a tip section of said borescope plug. 
 
     
     
       8. The gas turbine engine of  claim 7 , wherein said gas turbine engine structure is a mid-turbine frame. 
     
     
       9. The gas turbine engine of  claim 8 , wherein said mid turbine frame is mounted within an annular outer turbine exhaust case. 
     
     
       10. The gas turbine engine of  claim 9 , further comprising a multiple of centering pins engaged with said multiple of bosses. 
     
     
       11. The gas turbine engine of  claim 10 , wherein said borescope plug is mounted within said borescope boss. 
     
     
       12. The gas turbine engine of  claim 7 , wherein said borescope plug includes a shaft section and said tip section defines a diameter smaller than said shaft section. 
     
     
       13. The gas turbine engine of  claim 7 , wherein said tip section includes a semi-spherical tip. 
     
     
       14. A method of sealing a borescope inspection port comprising:
 interfacing a borescope plug upon a bushing to couple a first gas turbine engine structure to a second gas turbine engine structure; 
 interfacing said borescope plug upon a seal to provide sealing; and 
 permitting axial and radial movement of said seal relative to a tip section of said borescope plug. 
 
     
     
       15. The method as recited in  claim 14 , further comprising locating said bushing and seal in a borescope bore through one of a multiple of bosses. 
     
     
       16. The method as recited in  claim 15 , wherein said second gas turbine engine component is a mid-turbine frame. 
     
     
       17. The method as recited in  claim 16 , wherein the other of said multiple of bosses receive a support pin which extends through said first gas turbine engine component. 
     
     
       18. The gas turbine engine of  claim 7 , further comprising:
 an outer turbine exhaust case; 
 an inner case; and 
 a multiple of centering pins, 
 wherein said gas turbine engine structure defines a multiple of stators, and 
 wherein said multiple of centering pins are circumferentially distributed between said stators to engage said bosses to locate said gas turbine engine structure with respect to said inner case and said outer turbine exhaust case. 
 
     
     
       19. The gas turbine engine of  claim 7 , further comprising:
 an outer turbine exhaust case; and 
 an inner case, 
 wherein said borescope plug is a structural member of a load path between said outer turbine exhaust case and said gas turbine engine structure, and 
 wherein said borescope plug engages said borescope boss to locate said gas turbine engine structure with respect to said inner case and said outer turbine exhaust case. 
 
     
     
       20. The gas turbine engine of  claim 13 , wherein said semi-spherical tip is flush with an outer boundary of a primary gas path of the gas turbine engine.